Simulation of a wave impact using ReFRESCO pressure-based compressible-incompressible flow solver

ReFRESCO is a flow solver (Klaij et al., 2018) developed with maritime applications in mind. Therefore, in its original formulation, single and multiphase fluids are assumed to be incompressible. However, there are applications, such as slamming or sloshing, where compressibility effects need to be modelled. The first step to include compressibility effects in ReFRESCO was to implement and test a singlephase pressure-based compressible solver (Muralha et al., 2020). Having verified and tested the singlephase compressible solver, the development moved on to the multiphase solver. During the development of the multiphase flow solver, three test cases were used to check if the solver was ready to simulate practical applications. The first test case tested if the solver could sustain the hydrostatic equilibrium for a two-dimensional domain, the other test cases tested the solver for the compression and expansion of the compressible phase. These cases are the horizontal and vertical one-dimensional movement of a liquid piston between two compressible air pockets Muralha et al. (2022). This paper presents the calculation of a wave impact that results from the propagation of a wave in a flume tank, for which there are experimental results available. Results of the newly developed incompressible-compressible solver are compared with the fully incompressible solver and experimental data. Furthermore, numerical uncertainties of the selected quantities of interest obtained with the two solvers are estimated using simultaneous grid and time refinement in a set of geometrically similar grids.